Friction-clutch.



vsa

' 'WILLIAM H. saNDrom-i, or ARMAGH, IRELAND.

rnIcTion-nu'ron.

T-al'thom it mag/"concern: i 'j Be 'it known that I; WILLIAM' HERBERT SaNDroI'zn; afsubjegt of the King ofGreat Britain,l residingfi'n Armagh, Ireland, have' inventedcertain 'new and useful Improvements in Friction-Clutches, of, which the f following is a specification..

. The'present invention relates to a friction clutch.` .Accordingto thepresent inventionthe friction surfaces-'are brought into or' out' of contact by the,r displacement` of the vpoint -of application of apressure exertlng means along a pivoted'me'mber connected toone of the friction parts. 1 A' force acts vagainst la 'lever s o arranged that indisplacing the point of application ofthe Said force along thelevers with reference to its'fulcrum no substantial'worlr is done, thus reducing thel efi'o'rltnecessary to actuate the clutchfor the 'like to 'a mamma.;

-lhe inventlon-is'lllustrated by wayl of lexample only as applied .to a form of fric tionclutch.. x A

'In' the'drawings:-Figure 11's a sectional elevation of one form of construction. Fig.

2 is a frontelevation. of the Same, partly 1n section. Fig. 3 is a detail vView of a modii- The shaft 1 which'may ,for example bethe' driving shaft, carries 'a friction drum 2 onv vthe inside of' 'which friction -shoes 3 are adapted torbear.

5 so thatthe mechanism is properly poised and when they vare revolving about 'the' centertheshoes will'not fly driving.shaft-1,g asfsho'wn. The shoes carry side brackets 9. 'In these .brackets 9 slotted guides 12 areprovided forming slide surfaces for pins which aire further provided justment13. v"'llhe'sesleeves 11 engage in the Slotted portions' 14 in lever arms 15 pivoted att/17.6' t the'plte 6. The slotted portions lfl la'lre differentially inclined with reference to the'slotted portions 12 so that by an adj-ustxnentI of the screw'and nut connection Alfithe' pins 10 may be` displaced radially so as to adjust the position of the levers 15 when'the shoes 3 .are in contact with theirv v ibearing surface 2. The levers 15 are 'pro- The friction shoes 3 are, carried ul'ionpivots-l and provlded with counterweights 4 specification of Letters Patent. Patented Jan, 4, 1916 .l Application 'led April 22, 1915,. Serial No. 23,071. .v l f vided with operating surfaces such as 17 l lsubstantially concentric when'adjusted with vthe center` of rotation of the carrierhereinafter described. Operating membershaving rollers- 18 at their ends are adapted to 'engage said surfaces17 .and -are carried by a Sleeve 1.9. spindles 20 suitably mounted in the sleeve v19 and springs 21, are arranged between av ioating ring 37 and collars on the spindles which latterar'eJ preferablyscrewed there on so that the tension of the springs 21 and 'consequently the pressure of the rollers 18 v onfthe frictionsurfaces 17 of the levers 15V may be adjusted. It will be seen, therefore,

Rollers 18 are carried' upon.

pass the pivot 16 and come upon the eXtended portions 22 of the levers 15, then the shoes `-3 will be drawn away from the friction surfaces 2. -Of course it will be seen' that the greater the distance on the other side of the pivot 16 toward the ends 23 of these operating levers 15. the greater will be the effec-- tive pressure of the shoes 3 on the surface 2. 'A very eflicient variable friction clutch is thereby obtained whereby the degree of engagement between the clutching surfaces can be varied from the zero to the maximum,

4while the` operating pressure remains the .same andthere is no substantial' lineal disv placement ofthe pressure' and consequently small effort is required to actuatethe clutch.

.The ends 23 of the levers 15 are preferablymounted as shown and pointers 24 are preferably adjustably mounted on the plate 6 to facilitate the adjustment of the levers 15. The light springs 25 connected adjust-A ably with the levers 15 and the disk-6 assist'to just brin the friction surfaces into contact when t e pressure rollers 18 lie nearly in radial line with the pivots 16 of levers. These ends of the levers 15 also carry rollers 26 which are adapted to cooperate with Acarri surfaces 27 on the plate 28 connected with the sleeve '19. 'quently it will be seen that by turning around the sleeve 19 with the plate 28 f-rom Consesaid operating levers 15 and consequently Ahave small turning moment upon Vthe said the positionshown in Fig. 2 the pressure..

between the friction shoes 3 and the surface 2 will gradually be released as therollers 18.

move toward the pivot 1G of the koperating levers 15. On. further movement of the plate 28 the cams 27 will come into'the path of the rollers 26 and consequently turn these levers 15 about the pivots 16 as the radial distance of these rollers 26 from the center Will ,be decreased thereby bringing the shoes 3 completely out of engagement with the friction surface 2.

The portions 22 on the end of the levers 15 are preferably arranged' of 4such curvature that the pressure of the springs 21 on the spindles 2O carrying the roller 18 remains constant when the rollers 18 pass on to such portions when the clutch surfaces are out of engagement.

Any. desired means may be arranged for the turning of the sleeve 19 and therewith the disk 28 and preferably the sleeve 19 carries an internal threaded nut'29 engagin with a worm 30 which can be displaced axially on the drivenshaft 7 by the engagement of the roller 36 with the sleeve 31, which roller' 36 is mounted on the end of a lever 32 which may be a hand or a foot lever, as desired, and which turns about a suitable pivot. A spring 33 is adapted to pull on the lever 32 such that the worm 30 is moved axially to leep the rollers 18 at the farthest distance possible from the pivot 16, thereby arranging'that the friction surfaces are held normally in engagement at maximum pressure.

It Will be noticed that the spring 33 merely requires to be of such tension that it will overcome the friction between the nut 29 and worm 30 and the slight friction in moving the rollers 18 along the cam pat-hs 17 of the operating levers l5. In the same way to disengage the clutch pressure on the foot pedal or hand lever connected to the lever will only require to be such as to overcome the slightpressure of the spring 33.

In the modified form as shown in Fig. 3 multiple engaging surfaces 34 are shown on. the .friction shoes engaging with correspond- 'ing surfaces 35 on the inner side of the friction drum The friction surface on the brake shoes and brake surface of the drum may be increased as found suitable.

I declare that what I claim isz- 1. A rotary friction clutch comprising inner andouter relatively movable frictional iparts, a pivotally mounted operating lever actuating" said inner frictional part, a spider ciarrying said inner frictional part, acounterweight on said spider connected to said inner frictional part to avoid the eect of centrifugal force, pnessure means for exerting force on said operating lever, and means yto change the moment of said force about the fulcrum of said lever.

v2. A rotary friction clutch comprising,

Llevar:

in combination, a frictional drum, a spider ,mounted to rotate relatively to said drum,

erating on said levers, and means for changing the point of application of said pressureexerting means upon said levers, relatively to the lever fulcrums.

4. A friction clutch, comprising in combination a friction drum, a spider, friction shoespivoted on said spider, in operative relation to said drum, counterweights on said shoes, levers connected with said shoes, pivots carrying said levers, cam surfaces on said levers, pressure exerting means operating on said cam surfaces, and means to displace said pressure exerting means along said cam surface.

5. A friction clutch comprising a friction drum, friction shoes, pivots carrying said shoes, counterweights on said shoes preventing displacement of said shoes about said pivots due to centrifugal force, means for exerting pressure on said shoes and means for displacing the point of application on said pressure exerting means relatively to the pivots of said shoes.

6. A friction clutch comprising a; friction drum, friction shoes, levers connected to said shoes, pivots carrying said shoes, counterweights on said"shoes,l pivots carrying said levers, means for exerting pressure on said levers, and means for displacing the point of application of said pressure exerting means relatively to the pivots of said levers.

7. A friction clutch comprising a friction drum, friction shoes, pivots carrying said shoes, adjustable means for exerting pressure on said shoes, and means for displacing the point of application ofV said pressure exerting means relatively to the pivots of said shoes. Y v

8. A friction clutch comprising a friction drum, friction shoes, levers linked to said shoes, pivots carryingsaid levers, adjustable means for exerting pressure on said levers and means for displacing the point of application of said pressure exerting means relatively to the pivots of said levers.

9. A friction clutch comprising a friction drum, friction shoes, levers linked to said shoes, pivots carrying said levers, means for exerting pressure on said levers, means iat . said shoes, pivots carrying said counter-weights on said shoes, pivots carry# ressure exerting means relatively to of said levers, and positive means for disengaging said shoes from said friction drum.

10. .A friction clutch comprising a friction drum, friction shoes, levers connected to shoes,

for exerting pressure on for displacing the point said pressure exerting ing levers, means said levers, means of application of Y means relatively to the pivots of said levers,

.and positive means for disengaging said shoes from said friction drum.

11. A friction clutch comprising a friction drum, friction shoes, pivots carrying said shoes, levers connected to said shoes,

pivots carrying said levers, pressure plungers engaging said levers, a sleeve carrying said pressure plungers, and means for displacing said sleeve sothat the point of application of said pressure plungers on said levers is altered, relatively vto the Apivots 'ai-rying said levers.

12. A friction clutch comprising a friction drum, friction shoes, pivots carrying said shoes, levers connected to said shoes, pivots carrying said levers, spring plungers engaging said levers, a sleeve carrying said spring plungers, and means for displacing said sleeve so that the point of application of said spring plungers onrsaid levers is altered relatively to the pivots carrying said levers. l

13. A friction clutch comprising va friction drum, friction shoes, pivots carrying said shoes, levers connected to said shoes, pivots ,carrying said levers, spring plungers engaging said levers, a ring `carrying said 4spring plungers, and means for turning said so that the point of ap ring about its center plication of said spring plungers on said levers is altered, relatively to -the pivots carrying said levers. g

14. A friction clutch .comprising a friction drum, friction shoes, pivots carrying said shoes, levers connectedto said shoes, pivots carrying saidv levers, pressure plungers engaging said levers, a sleeve carrying said pressure plungers, means for adjusting the thrust of said pressure plungers and means for displacing said sleeve so ,that tne point of application of said plungers onl said levers'is shifted relatively carrying said levers.

In witness whereof, I have hereunto signed my name this 3rd day of April, 1915, in the presence of two subscribing Witnesses.

WILLIAM SANDFORD.

Witnesses:

REGINALD W. KIDDLE, HENRY W. Asco'r'r.

to the pivots topiesl of this patent maybe obtained for ve cents each, by addressingv the Commissioner of Patents. Washin'gtoml). C. 4 

